J.W. Sa

Status of the KSTAR Tokamak Construction

The KSTAR is a superconducting tokamak under construction at the Korea Basic Science Institute (KBSI) in Daejeon, Korea. The project mission aims at a steady-state operation and advanced tokamak physics. At present, the project is in the peak of fabrication and assembly phase. The fabrication of the major tokamak structures such as vacuum vessel, cryostat, port system, thermal shields, and gravity support, is completed. The manufacture and testing of the 30 superconducting magnets are rigorously being progressed. As of Sep. 2005, 16 toroidal field coils and 4 large poloidal field coils are completed. To verify the operational feasibility of the KSTAR coils, cool-down and current charging tests of a real sized prototype TF coil and a pair of CS model coil have been carried out. The assembly of the device has begun from beginning of 2004. Now, the vacuum vessel body, thermal shields and 8 toroidal field magnets are assembled on the tokamak position. Assembly finish is scheduled for August 2007. This paper describes the manufacture and assembly progress of the KSTAR tokamak

CONSTRUCTION, ASSEMBLY AND COMMISSIONING OF KSTAR MAIN STRUCTURES

The KSTAR device succeeded in first plasma generation on June of 2008 through comprehensive system test and commissioning. Among various kinds of the key factors that decisively affected the project, success in the construction and assembly of the major tokamak structure was most important one. Every engineering aspects of each structure were finally confirmed in the integrated commissioning period, and there were no severe troubles and failures prevented the KSTAR device from operating during the commissioning and the first plasma experiments. As a result, all of the experiences and technologies achieved through the KSTAR construction process are expected to be important fundamentals for future construction projects of superconducting fusion devices. This paper summarizes key engineering features of the major structures and of the machine assembly.

Structural analysis of the KSTAR toroidal field magnet system

The toroidal field (TF) magnet system of Korea superconducting tokamak advanced research (KSTAR) device consists of 16 superconducting coils enclosed in the steel cases. The TF magnet structure protects the winding pack from mechanical, electrical, and thermal loads, and also supports three pairs of poloidal field (PF) coils as well as four pairs of central solenoid (CS) coils. A three-dimensional finite element (FE) model including the winding pack, insulation and filler material has been developed using solid brick elements, and a hybrid model with beam-shell elements has been also built for the verification purposes. The structural reliability of the TF magnet system is investigated by performing various analyzes such as a global/local analysis, a detailed analysis, and a fatigue evaluation. The results reveal that the maximum stress intensities of the TF magnet structure are below the allowable stress limit and its fatigue life complies with the requirements of the design criteria, so it can safely withstand the reference scenario operations. In addition, the design loads obtained from analysis results can be used for the detailed structural design of other supplementary components.

Final design and start of manufacture of the ITER Vacuum Vessel ports

The ITER Vacuum Vessel (VV) features upper, equatorial and lower ports. Although the port design has been overall completed in the past, the design of some remaining interfaces was still in progress and has been finalized now. As the ITER construction phase has started, the procurement of the VV ports has been launched. The VV upper ports will be procured by the Russian Federation DA, while the equatorial and lower ports will be procured by the Korean DA. The main industrial suppliers were selected and development of the manufacturing design is in progress now. Since the VV is classified at nuclear level N2, design and manufacture of its components are to be compliant with the French code RCC-MR and regulations of nuclear pressure equipment in France. These regulations make a strong impact to the port design and manufacturing process, which is in progress now.

Design and manufacture of the ITER Vacuum Vessel

The main functions of the ITER Vacuum Vessel (VV) are to provide the necessary vacuum for plasma operation, act as first nuclear confinement barrier and remove nuclear heating. The design of the VV has been reviewed in the past two years due to more advanced analyses, design modifications required by the interfacing components and R&D. Following the signature of four Procurement Arrangement (PAs), the manufacturing design of the VV sectors, ports and In-Wall Shielding (IWS) is being finalized and the fabrication of the VV sectors has been started in 2012.

Fabrication Preparation of ITER Vacuum Vessel—Material Considerations, Regulatory Requirements, and Fabrication Plans

Abstract SS 316 L(N)-IG (ITER grade) has been selected as the main structural material for the ITER vacuum vessel (VV), considering its high mechanical strength at operating temperatures, water chemistry properties, excellent fabrication characteristics, and low cost relative to other candidates. The ITER VV is a class-2 box structure as defined in RCC-MR, 2007 edition, which was selected as the code for the design and construction. This paper describes materials, applied code and regulatory requirements, baseline fabrication procedures, and assembly on the site.